Browser Color-Correction Test Page

This page was created in order to test whether browsers implement color
correction or not. Modelled after a similar test for MNG images
by Gerard Juyn, the concept is quite simple: if all three of the images
in each row look the same, the browser passes. If they're all different,
it fails.

Specifically, the pixel data in two of the three copies of the image were
modified. The left image has had its red and green channels swapped,
while the right image has had its red and blue channels swapped. (The
center image is the original, of course.) In each case, the corresponding
color-space chunks have been similarly modified to cancel out the color-swap,
which is why the images will look the same on browsers that fully implement
color correction according to the PNG specification.

The first row uses the (simple) PNG chromaticity chunk, cHRM:

The second row uses a full (though fairly basic) ICC profile embedded in the
PNG iCCP chunk:

Both rows should look approximately like this, if the browser does
color correction properly:

If the rows instead look like this, the browser does not support
color correction: